Stop motion with built-in slub catcher



June 18, 1968 L. MISHCON STOP MOTION WITH BUILT-IN SLUB CATCHER FiledJan. 30. 1967 INVENTOR Lester Mishcon BY I Witness ATTORNEY UnitedStates Patent 3,388,565 STOP MOTION WITH BUILT-IN SLUB CATCHER LesterMishcon, Miami Beach, Fla., assignor to The Singer Company, New York,N.Y., a corporation of New Jersey Continuation-impart of applicationSer. No. 544,951, Apr. 25, 1966. This application Jan. 30, 1967, Ser.No. 612,411

2 Claims. (Cl. 66-161) ABSTRACT OF THE DISCLOSURE A stop motion devicefor a circular knitting machine is described as embodying a slub catcherin the nature of a pivotal arm of the stop motion device. The slubcatcher in one form of the invention takes the form of an elongated openended slot, and as presently preferred, the dimensions of such slot areadjustable to accommodate various and sundry forms of yarns.

Cross references to related applications United States application Ser.No. 544,951, filed Apr. 25, 1966, of which the present application is acontinuationin-part.

Background 0 the invention (1) Field of the inventi0n.Stop motiondevices for knitting machines are designed to interrupt power to suchmachines when yarn tension exceeds, or is less than, certainpredetermined amounts. Typical of known prior art stop motion deviceswith which the invention is practicable is the unit shown and describedin United States Patent No. 2,515,479. Various causes will effect anincrease in the tension of yarn fed to a knitting machine, least ofwhich is a slub of yarn that gets caught while passing through arestricted passageway, i.e. a slub catcher, toward the needles of themachine. The invention is directed to defining the specific nature ofjust such a restricted yarn slub catcher passageway, and the relation ofsuch slub catcher to its stop motion device, and also to the rest of theknitting machine.

(2) Description of the prior art.Prior to the invention of copen-dingapplication Ser. No. 544,951, slub catchers took the form generally ofcomponents with eyelets, or eyelets in combination with open endedslots, such being customarily situated between their respective cones ofyarn and their stop motion devices. As a result thereof, each strand ofyarn had to be of sufficient length from slub catcher to the needles ofthe knitting machine to permit proper yarn consumption after a givenstop motion device was actuated, and while the machine was therebyslowed down to a complete halt. This attendantly resulted in therequirements for a substantial overall height for prior art knittingmachines since the yarn from the cones had to pass upwardly throughtheir slub catchers to the stop motion devices, and then back downwardlyto the knitting machine needles. The cumbersome tallness of prior artknitting machines placed restrictive requirements on buildings etc. forhousing such machines, and also made the placing of yarn in respectiveguides of stop motion devices a tedious job. To lessen the overallheight of a knitting machine, copending application Ser. No. 544,951 hastaught the use of an open ended slub catcher, without eyelet typeguides, that so locates between a yarn cone and its stop motion devicethat the yarn, in the process of dropping from the slub catcher, andthereby actuating its stop motion device, provides the length of yarnnecessary to allow proper knitting while the machine comes to a halt.Such an open ended slub catcher was comprised of a bent wire formed toprovide a generally vertical slot, with its closed end upward, out ofwhich the yarn could drop when a slub caught within the slot, and causedthe stop motion device to release such yarn. While slub catchers of thistype have proven quite satisfactory, it has been found that much effortis involved in assuring the vertical orientation of the slub catcherslot; and also the arrangement thereof is not as compact and sturdy aswould be desired.

Summary of the invention Since stop motion devices use firmly supportedpivotal arms tosupport their respective strands of yarn, and since sucharms orient downwardly when pivoted in response to yarn tension, thepresent invention takes full advantage of such facts to avoid theproblems which the technique of copending application Ser. No. 544,951has presented. At least one pivotal arm of a stop motion device isdesigned to provide an elongated narrow open ended slot through whichyarn is ordinarily adapted to pass, whereby when a slub gets caught insuch slot, the tension within the yarn causes the stop motion yarnsupport arm to pivot, interrupting power to the knitting machine, and inso doing orients the slot downwardly to cause the yarn to drop from thestop motion device for consumption while the machine comes to a halt.Because the slub catcher of the invention is actually a stop motion yarnsupport arm that is firmly, though pivotally, supported by the stopmotion device, such arrangement is not only compact, but ofcomparatively rugged construction. And since the slot of the slubcatcher of the invention orients downwardly at the instant of yarnrelease, such slub catcher practices the invention of copendingapplication Ser. No. 544,951, deriving all of its advantages inpermitting of shorter knitting machines.

In its presently preferred form, the slub catcher of the inventionembodies an adjustable piece that serves to vary the dimensions of theslot of the slub catcher yarn supporting arm, whereby the invention maybe practiced for yarns of virtually any type.

A principal object of the invention is to provide a novel yarn slubcatcher for use with the stop motion device of a knitting machine, fromwhich slub catcher the yarn is adapted to be automatically released uponactuation of the stop motion device, this being to provide the requisiteslack in the yarn whereby yard breakage will be prevented from occuringat the knitting instrumentalities before the machine can be stopped.

Another object of the invention is to provide a stop motion devicehaving at least one arm adapted not only for supporting a strand ofyarn, but also for serving as a yarn slub catcher.

Another object of the invention is to provide a stop motion devicehaving at least one arm with an adjustable elongated slot that isadapted to serve as a yarn slub catcher.

The invention will be described with reference to the figures, wherein--FIG. 1 is a perspective view of a stop motion device embodying the slubcatcher of the invention,

FIG. 2 is a side elevational view of the stop motion device of FIG. 1,and

FIG. 3 is a slub catcher arm adapted to provide a presently preferredform of stop motion device according to the invention.

Referring to FIGS. 1 and 2, a stop motion device 10 for a knittingmachine has a pair of spaced apart yarn support arms 12, 14, which armsare pivotally supported on a shaft 16. The shaft 16 mounts within thehousing of the stop motion device 10 and is so spring-biased, by meanswithin the housing of the stop motion device 10, that the arms 12, 14ordinarily orient to bear generally against stops 18, 20 provided by aplate 22 as shown in FIG. 2.

Electrical power is supplied to the stop motion device via a contactclip 24'that is electrically coupled to a switch within the housing ofthe stop motion device 10, but which clip 24 is electrically insulatedfrom such housing. The electrical switch, as indicated in both copendingapplication Ser. No. 544,951 and United States Patent No. 2,515,479, isactuated by means of the yarn support arms 12, 14 and, when such armsare as depicted in FIG. 2, the switch permits of power to drive theknitting machine, whereas with the arms 12, 14 depicted as in FIG. 1,power is cut off from the knitting machine. The electrical circuit,including the aforementioned switch, is completed through the housing ofthe stop motion device 10, which housing is adapted to secure, by meansof a flange 26, to a grounding ring of the knitting machine, such ringbeing adapted to reside within the cutout 28 of the flange 26.

The housing of the stop motion device 10 pivotally supports, also, ashaft 30 that is bent at 32, and is adapted to accommodate acounterweight 34. The shaft 30 supports a yarn engaging flange element36, and is so biased by the counterweight 34 that, absent the presenceof yarn Y across the flange element 36, the flange element 36 orients asshown in FIG. 2. Customarily, however, the yarn Y resides across theflange element 36 and between such element and a plurality of U-shapedguides 38 that aresecured to the housing of the stop motion device 10.The U-shaped guides 38 in combination with the yarn Y prevent the flangeelement 36 from taking its FIG. 2 position, whereby a switch (within thehousing of the stop motion device) operable by rotation of the shaft 30will actuate the stop motion circuit of the knitting machine. Asexcessive amount of yarn tension causes the arms 12, 14 to pivotdownwardly to initiate the stop motion switch; too little yarn tension,as would occur were the yarn Y to break, causes the flange element 30 topivot upwardly to initiate the stop motion switch. This is all wellknown in the art as indicated by both of the abovementioned references,and no claim is herein made to the inner workings of stop motion devicesper se.

The invention is directed to a particularly way of producing yarntension, whereby the stop motion device involved will become actuated inresponse to the presence of a slub etc. in such yarn. Referring again toFIGS. 1 and 2, the arm 12 is shown having a conventional U-shaped yarnguide 40; the arm 14 is shown however having an open ended guide slot 42that is just sufficiently wide to accommodate the passage therethroughof the yarn Y. When for example a slub S of yarn passes easily throughthe guide 40 of the arm 12 to the guide slot 42 of the arm 14, such slubgets caught against the sides of the slot 42, thereby causing thetension of the yarn Y to build up as the knitting machine in questioncontinues to demand yarn. Such tension causes the arms 12, 14 to bepulled downwardly, thereby initiating the stop motion switch. With theknitting machine continuing to knit while con1- ing to its halt, theyarn Y is pulled from the guide slot 42 (and also from the guide 40),thus releasing the flange element 36 to its FIG. 2 position to continuethe stop motion command, and providing the slack length of yarnnecessary for knitting purposes during the halting of the knittingmachine. Reflecting on the teaching of copending application Ser. No.544,951, a narrow open ended slot is again employed to effect yarntension in response to a yarn slub S; further, the slot guide 42releases the to knitting needles, the amount of yarn given up onactuation of the stop motion device 10 is sufiicient to permit properknitting while the machine comes to a halt, this being before the slub Sreaches the knitting instrumentalities of the machine.

Since yarns may be of different sizes and consistencies, it has beenfound advisable to provide adjustability to the slub catching slot ofthe stop motion device yarn support arm, whereby stop-motioning may beproperly'etfected regardless of yarn type. Referring now to FIG. 3, apresently preferred form of slub catching arm 12 for use by a knittingmachine stop motion device supports two spaced apart adjustment screws44. The screws are adapted to reside in respective elongated slots 46 inan adjustment piece 48 and, when tightened against such piece 48, holdsame in place against the arm 12'. For lightweight yarns, the piece 48is so positioned that-the slot 42 is just sufliciently wide to pass theyarn, whereas for heavier yarns the slot 42 is made correspondinglywider.

While the invention has been described in its preferred form it is to beunderstood that the words which have been used are words of descriptionrather than of limitation, and that changes within the purview of theappended claims may be made without departing from thetrue scope andspirit of the invention.

Having thus set forth the nature of this invention, what is claimedherein is:

1. In a stop motion device (10) for knitting machines, which stop motiondevice (10) is of the type having a yarn supporting arm (14) that is soshiftable that its longitudinal axis may point generally downwardly inresponse to yarn tension to actuate a stop motion switch thereof whensuch yarn tension is in excess of a predetermined amount,

the improvement wherein such arm (14) is provided with a substantiallylongitudinal open ended slot (42) that is adapted to permit easy passageof yarn (Y) therethrough, but which slot is sutficiently narrow toprevent passage therethrough of a yarn slub (S) or the like, wherebywhen a slub engages the slot said supporting arm is shifted downwardlyto cause said yarn to fall free.

2. The apparatus of claim 1 including means (48) cooperative with saidslot to vary the dimensions of said slot to accommodate easy passagetherethrough of various forms of yarns, but not the passage therethroughof respective slubs of said various yarns.

References Cited UNITED STATES PATENTS 2,010,928 8/1935 Quick 66-1632,362,781 11/1944 Tellerman 66 -163 2,434,864 1/1948 Powell 66l63 XR2,515,479 7/1950 Vossen 2006l.l3 2,825,214 3/1958 Pernick 66-1633,001,389 9/1961 Vossen 66163 FOREIGN PATENTS 51,630 6/1910 Switzerland.

WILLIAM CARTER REYNOLDS, Primary Examiner.

yarn when such slot is oriented generally downwardly; and since-noeyelet guides are employed from yarn cone

